Disclosed herein is a surround audio dialog balance assessment method, apparatus, and system, and more particularly, disclosed herein is a surround audio dialog balance assessment method, apparatus, and system that is an audio monitor or is associated with an audio monitor.
Audio is very important in “broadcast programs” (also referred to as “programs”) such as television or film programs. One type of audio is “surround sound” (also referred to as “surround”). The surround sound for a broadcast programs may be referred to as “surround sound programs” or “surround programs.” Surround sound encompasses a range of techniques for reproduction of an audio source (including at least one audio signal) with audio channels (including at least one audio signal) reproduced using multiple discrete speakers. A surround sound system creates the illusion of multi-directional sound through speaker placement and signal processing. Surround sound is characterized by a listener location or sweet spot where the audio effects work best, and presents a fixed or forward perspective of the sound field to the listener at this location. One exemplary type of surround sound has five channels: center front channel CF, left front channel LF, right front channel RF, left surround channel LS (left rear channel), and right surround channel RS (right rear channel).
It is common practice in television and film production to place dialog (e.g. speech such as spoken voice(s) of people, characters, and/or narrators) only in the center front channel. For purposes of description, the center front channel will be used as an exemplary dialog transmitting channel. Ambient sounds, sound effects, and music (“competing program content”) are placed in the other four surround channels and in the low frequency effects (LFE) channel. It is the mix engineer's job to balance the audio signal content in each channel to make a pleasing and realistic audio presentation that complements the visual presentation. The balance between the dialog and the competing program content between channels is sometimes called “channel balance.”
When mixing surround programs, it is important to keep the dialog louder than the competing program content so the dialog remains intelligible. As a guide to accomplishing this, professional sound mixers are often instructed to maintain a minimum level difference between the center front and the left and right front channels. The levels (typically measured using volume unit (VU) meters or peak program meters (PPM)) of these three front channels are displayed on meters of virtually all mixing consoles FIG. 1. The meters are usually in close physical proximity to each other, typically arranged in the order left front 110, right front 120, and center front 130. This makes comparisons between the channel levels shown on the meters relatively easy, and thus the visual comparison technique has become a common practice.
The left and right front levels are often, but not always, representative of the overall surround program level. A common exception is when mixing live sports and crowd noise occurs in the surround channels 150, 160. In this situation a better guideline would be to compare the center front level to each of the other surround channels in the surround program. However, this would be far more difficult because of the larger number of meters involved, their larger physical separation in a typical console, and the presence of the LFE channel meter 140, usually next to the center front meter 130, which would not be involved in the comparison.
Even when performing the simpler task of comparing center front level to the left and right front levels, continuous attention is required. If the user is not looking at the meters, intelligibility may inadvertently drop to an unacceptable level.
Known systems are described in U.S. Pat. No. 8,050,434 to Kato et al., U.S. Pat. No. 7,929,717 to Okabayashi et al., and U.S. Pat. No. 5,930,375 to East et al. These references are specifically incorporated by reference herein.